The present invention relates to a friction lining material for use in applications such as brakes and clutches, which is of the kind containing mineral fibres, organic fibres, fillers and a binder.
The fibres used can be presented in various forms, for example they may be free fibres, threads of continuous or discontinuous fibres, rovings, strands, mats, felts, fibrics and the like.
Hitherto, the organic fibres have generally been intended to improve the spinning conditions of the mineral fibres, that is to say for manufacturing reasons, rather than to improve the rubbing performance.
In fact, hitherto, the organic fibres have reputedly been more harmful than useful for the actual service of the lining. It is for this reason that they have generally been chosen in the form of cellulosic fibres, animal fibres, vegetable fibres or the like, that is to say in the form of an infusible type in which the fibre does not liquefy when the temperature of the lining rises during service, but decomposes without disturbing the rubbing conditions of the lining.
Infusible organic fibres of this type can have a moderating effect on the more or less aggressive action of the mineral fibres (and particularly glass fibres), on the counter-material, i.e. the material against which they are applied, for example the drum, disc, crown wheel, plate or the like, against which the lining is allowed to rub. However, these infusible organic fibres have the major disadvantage of reducing wear resistance of the lining itself.
The present invention provides a friction lining material, in particular for brakes, clutches and other applications, which is of the kind containing mineral fibres, organic fibres, fillers and a binder, which is free of these various disadvantages and in which the wear resistance of the lining is excellent.